=================
Future Directions
=================

This section describes ideas and proposals for future versions of the PDN standard.

Alternative move disambiguation
--------------------------------

.. admonition:: Proposal
   :class: proposed

   The current way of move disambiguation (see section :ref:`grammar-section`) was chosen for backward compatibility.
   The following alternative is proposed. An ambiguous move is written as usual, followed by the sequence of
   captured squares between angular brackets ``<`` and ``>``. For example, in the following position

   .. image:: diagram1.png

   the two possible captures are written as ``47x36 <42, 29, 14, 31>`` and ``47x36 <42, 29, 19, 31>``. The
   motivation for this is that it is less complicated to implement, and easy to understand for humans.

Demo annotations
----------------

.. admonition:: Proposal
   :class: proposed

   In chess, it is common practice to embed graphical annotations directly in the move sequence using
   embedded commands. Lichess and ChessBase, among others, support ``[%csl ...]`` (colored squares)
   and ``[%cal ...]`` (colored arrows), where each entry is a color code followed by a square
   name, e.g. ``[%csl Rf4,Ge5]`` highlights f4 in red and e5 in green, and ``[%cal Ge2e4]`` draws
   a green arrow from e2 to e4.

   A similar convention could be adopted for PDN, using square numbers instead of algebraic names:

   - ``[%csl R12,G23]`` — highlight square 12 in red and square 23 in green
   - ``[%cal R12-23]`` — draw a red arrow from square 12 to square 23

   For move demonstrations, an additional ``[%animate]`` command could signal to a viewer that
   the variation should be played back automatically, which is useful for instructional material.